The concept of waterproof twist-on wire connectors wherein a sealant is placed in the cavity of a twist-on wire connector is known in the art and is shown in U.S. Pat. Nos. 5,113,037; 5,023,402 and 5,151,239. In these type of connectors the wires are inserted through a pierceable cover and into a sealant in the twist-on wire connector cavity. In some embodiments sleeves are placed on the wire connector to contain extra sealant. In a further embodiment the connector includes clips for looping the wires thereon to prevent the wires from pulling out of the twist-on wire connector.
A system widely used in installing underground electrical systems, is known as a direct bury splice kit. The kit includes, a twist-on wire connector, a housing with an integral cover that is closeable on the wires to provide stain relief. One such kit is sold by the 3M electrical products of Austin Tex. The kit comprises a twist-on wire connector that contains no sealant and an elongated tube that contains a sealant. The twist-on wire connector and the tube are both stored loosely in a plastic package that must be breached before the twist-on wire connector and the elongated tube can be used. The elongated tube contains a sealant in a closed end of the tube and a cover proximate an open end of the tube. The cover can be closed on wires extending into the tube to provide strain relief.
While the Direct Bury Splice Kit is an effective solution for underground burial of electrical splices in order to use the 3M Direct Bury Splice Kit one must first remove both the twist-on wire connector and the elongated tube from a shipping package. One then secures the twist-on wire connector to the wires. Next, the twist-on wire connector is inserted into the sealant in the closed end of the elongated tube. The twist-on wire connector is then forced downward into the sealant until the twist-on wire connector extends past locking fingers, which are located on the inside of the tube, to thereby lock the twist-on wire connector in the elongated tube to prevent withdrawal of the twist-on wire connector. Finally, the cover, which is attached to the tube, is closed to hold the wires in the tube. The direct bury kit is then ready for burial. However, if the connection needs to be changed, that is if one discovers an additional wire needs to be included in the splice in the twist-on wire connector or if the splice needs to be reworked one must either cut the wires and use another direct bury splice kit or cut the elongated tube to free the twist-on wire connector which enables one to reuse the twist-on wire connector. If the wires are cut the remaining wires might not be long enough to make a new connection. On the other hand, if the wires and twist-on wire connector are removed from the tube a new tube is required since the tube needs to be destroyed to remove the twist-on wire connector which is locked therein by locking fingers on the tube walls. In addition, once the twist-on wire connector is removed from the tube the exterior of the twist-on wire connector is covered with sealant making it difficult to handle and reuse the twist-on wire connector to secure a new connection therein.
In contrast to the prior art 3M Direct Bury Splice Kit the present invention provides a direct bury twist-on wire connector that is an integral part of a one-piece tube, which eliminates the handling of a separate wire connector that is susceptible to being lost when the shipping package with the direct bury twist-on wire connector is opened. In the present invention, the wires to be connected are inserted directly into the twist-on wire connector that is integral with a tube having a closure thereon. The outer portion of the twist-on wire connector forms part of an exterior portion of the tube to enable one to grip the twist-on wire connector for rotation thereof and the inner portion of the twist-on wire connector cooperates with tube to carry the sealant. When the tube with the integral twist-on wire connector is rotated with respect to the wires it brings the electrical wires into an electrical connection. Once the cap is closed the direct bury connector of the present invention inhibits strain on the wires therein through pressure engagement between the cover and the tube leaving the direct bury connector ready for underground burial.
An advantage of the present invention over the direct bury splice kit is that if additional wires need to be added or if the splice needs to be reworked the direct bury connector can be reused without the user having to handle a sealant covered twist-on wire connector. A further advantage is that if a rework of the splice or if additional wire are required the user does not have to cut away the old elongated tube and insert the twist-on wire connector into a new elongated tube of sealant since the tube of direct bury connector of the present invention can be reused. Thus, not only is the present invention more convenient to use it generates less waste.